To evaluate the efficacy of CT- guided biopsy in the diagnosis of mediastinal lesions compounded with PET/CT mapping prior to biopsy in a 30 day time interval from the biopsy day.

This is a single centered retrospective study in a cohort of 36 patients referred to our department the last 24 months ( October 2016- October 2018) with a diagnosed mediastinal lesion, between 32-74 years old, 21 males and 15 females. 32 lesions were located in the anterior mediastinum and 4 in the posterior. A pre biopsy PET/CT scan was available in 19 out of these 36 patients. All patients were informed about the necessity of obtaining tissue sample from the lesion, the procedure of CT...

A definitive diagnosis was achieved in 34/36 patients with a 94,4 % success rate. 32 lesions were located in the anterior mediastinum including 22 Hodgkin lymphomas , 5 small cell lung carcinoma, 2 non Hodgkin lymphomas, 1 Thymoma, 1 hamartoma and 1 sarcoma. 4 lesions were located in the posterior mediastinum including 3 non Hodkin lymphomas and 1 neuroma. The two inconclusive cases concerned non Hodgkin lymphomas located in the posterior mediastinum. Surgical intervention provided the diagnosis.

Our restrospective study provides support for the use of FDG- PET/CT to improve the diagnostic accuracy of percutaneous CT-guided mediastinal biopsy, guiding the operator to the most metabolically active area of the lesion. It consequently, reduces the potential need for repeated invasive procedures- multiple needle passes for obtaining tissue sample and the risk of complications. Whilst, PET/CT does not offer extra information from CT or MRI scans conserning tumor necrosis. In one case we changed initial biopsy plans due to PET/CT, because we felt it...

Danai Stefanou, MD, Radiology Resident [email protected] Demetrios Exarhos,MD, PhD, Interventional Radiologist [email protected] Evangelismos Hospital, Department of CT-MRI & PET/CT, Athens, GR

1. Gupta, Sanjay, et al. "Imaging-guided percutaneous biopsy of mediastinal lesions: different approaches and anatomic considerations."Radiographics25.3 (2005): 763-786. 2. Fei, Baowei, and David M. Schuster. "PET Molecular Imaging–Directed Biopsy: A Review."American Journal of Roentgenology209.2 (2017): 255-269. 3. İntepe, Yavuz Selim, et al. "Our transthoracic biopsy practices accompanied by the imaging process: The contribution of positron emission tomography usage to accurate diagnosis."Acta Clinica Belgica71.4 (2016): 214-220. 4. Filippiadis, Dimitrios, et al. "Computed tomography-guided mediastinal biopsy: a single center’s experience focusing upon efficacy and safety."Hellenic Journal οf...